1 /*
2 * Copyright (C) 2001, 2002, 2003 Broadcom Corporation
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #include <linux/init.h>
20 #include <linux/delay.h>
21 #include <linux/interrupt.h>
22 #include <linux/smp.h>
23 #include <linux/kernel_stat.h>
24 #include <linux/sched/task_stack.h>
25
26 #include <asm/mmu_context.h>
27 #include <asm/io.h>
28 #include <asm/fw/cfe/cfe_api.h>
29 #include <asm/sibyte/sb1250.h>
30 #include <asm/sibyte/sb1250_regs.h>
31 #include <asm/sibyte/sb1250_int.h>
32
33 static void *mailbox_set_regs[] = {
34 IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_SET_CPU),
35 IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_SET_CPU)
36 };
37
38 static void *mailbox_clear_regs[] = {
39 IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CLR_CPU),
40 IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CLR_CPU)
41 };
42
43 static void *mailbox_regs[] = {
44 IOADDR(A_IMR_CPU0_BASE + R_IMR_MAILBOX_CPU),
45 IOADDR(A_IMR_CPU1_BASE + R_IMR_MAILBOX_CPU)
46 };
47
48 /*
49 * SMP init and finish on secondary CPUs
50 */
51 void sb1250_smp_init(void)
52 {
53 unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
54 STATUSF_IP1 | STATUSF_IP0;
55
56 /* Set interrupt mask, but don't enable */
57 change_c0_status(ST0_IM, imask);
58 }
59
60 /*
61 * These are routines for dealing with the sb1250 smp capabilities
62 * independent of board/firmware
63 */
64
65 /*
66 * Simple enough; everything is set up, so just poke the appropriate mailbox
67 * register, and we should be set
68 */
69 static void sb1250_send_ipi_single(int cpu, unsigned int action)
70 {
71 __raw_writeq((((u64)action) << 48), mailbox_set_regs[cpu]);
72 }
73
74 static inline void sb1250_send_ipi_mask(const struct cpumask *mask,
75 unsigned int action)
76 {
77 unsigned int i;
78
79 for_each_cpu(i, mask)
80 sb1250_send_ipi_single(i, action);
81 }
82
83 /*
84 * Code to run on secondary just after probing the CPU
85 */
86 static void sb1250_init_secondary(void)
87 {
88 extern void sb1250_smp_init(void);
89
90 sb1250_smp_init();
91 }
92
93 /*
94 * Do any tidying up before marking online and running the idle
95 * loop
96 */
97 static void sb1250_smp_finish(void)
98 {
99 extern void sb1250_clockevent_init(void);
100
101 sb1250_clockevent_init();
102 local_irq_enable();
103 }
104
105 /*
106 * Setup the PC, SP, and GP of a secondary processor and start it
107 * running!
108 */
109 static int sb1250_boot_secondary(int cpu, struct task_struct *idle)
110 {
111 int retval;
112
113 retval = cfe_cpu_start(cpu_logical_map(cpu), &smp_bootstrap,
114 __KSTK_TOS(idle),
115 (unsigned long)task_thread_info(idle), 0);
116 if (retval != 0)
117 printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
118 return retval;
119 }
120
121 /*
122 * Use CFE to find out how many CPUs are available, setting up
123 * cpu_possible_mask and the logical/physical mappings.
124 * XXXKW will the boot CPU ever not be physical 0?
125 *
126 * Common setup before any secondaries are started
127 */
128 static void __init sb1250_smp_setup(void)
129 {
130 int i, num;
131
132 init_cpu_possible(cpumask_of(0));
133 __cpu_number_map[0] = 0;
134 __cpu_logical_map[0] = 0;
135
136 for (i = 1, num = 0; i < NR_CPUS; i++) {
137 if (cfe_cpu_stop(i) == 0) {
138 set_cpu_possible(i, true);
139 __cpu_number_map[i] = ++num;
140 __cpu_logical_map[num] = i;
141 }
142 }
143 printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
144 }
145
146 static void __init sb1250_prepare_cpus(unsigned int max_cpus)
147 {
148 }
149
150 const struct plat_smp_ops sb_smp_ops = {
151 .send_ipi_single = sb1250_send_ipi_single,
152 .send_ipi_mask = sb1250_send_ipi_mask,
153 .init_secondary = sb1250_init_secondary,
154 .smp_finish = sb1250_smp_finish,
155 .boot_secondary = sb1250_boot_secondary,
156 .smp_setup = sb1250_smp_setup,
157 .prepare_cpus = sb1250_prepare_cpus,
158 };
159
160 void sb1250_mailbox_interrupt(void)
161 {
162 int cpu = smp_processor_id();
163 int irq = K_INT_MBOX_0;
164 unsigned int action;
165
166 kstat_incr_irq_this_cpu(irq);
167 /* Load the mailbox register to figure out what we're supposed to do */
168 action = (____raw_readq(mailbox_regs[cpu]) >> 48) & 0xffff;
169
170 /* Clear the mailbox to clear the interrupt */
171 ____raw_writeq(((u64)action) << 48, mailbox_clear_regs[cpu]);
172
173 if (action & SMP_RESCHEDULE_YOURSELF)
174 scheduler_ipi();
175
176 if (action & SMP_CALL_FUNCTION) {
177 irq_enter();
178 generic_smp_call_function_interrupt();
179 irq_exit();
180 }
181 }
182
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